Viral DNA synthesis in HCMV infected cells is not detectable until 48 hours p.i., a relatively longer period of time for the initiation of viral DNA synthesis as compared with other viruses. Since decisions about the infective process for lytic or abortive are probably made early, therefore, we will turn our attention to study the fate and intracellular forms of HCMV parental DNA in both permissive and abortive cell systems. Cells from both permissive and abortive systems will be infected with high titers of infectious virus with a high specific activity of H3-thymidine. The distribution of parental DNA between the cytoplasm and the nucleus at various times after infection will be determined. Patterns of replication of HCMV parental DNA from infected cells at various times p.i. will be analyzed by ultracentrifugation in both sucrose and cesium chloride gradient. Radio-labelled parental DNA will be separated from cellular DNA and characterized by electron microscopic observations. Furthermore, translational products of HCMV parental DNA from infected cells will also be analyzed by gel electrophoresis. BIBLIOGRAPHIC REFERENCES: Furukawa, T., Hornberger, E., Sakuma, S., Plotkin, S.A.: Demonstration of Immunoglobulin G Receptors Induced by Human Cytomegalovirus. J. Clin. Micro., 332-336 (Oct. 1975). Hirai, K., Furukawa, T., Plotkin, S.A.: Induction of DNA Polymerase in WI-38 and Guinea Pig Cells Infected with Human Cytomegalovirus (HCMV). Virology 70: 251-255 (1976).